Timothy Champion

Information for the present study has been gathered through a variety of methods over a considerable period of time. The original article (Champion 1980), followed especially by the detailed publication of some key assemblages such as the finds from Queen Mary’s Hospital, Carshalton (Adkins and Needham 1985) and Mucking North Ring (Bond 1988), drew attention to these artefacts and greatly increased the chances of their correct identification and publication. Monitoring of published excavation reports from the region therefore provided the first line of new information. Subsequent enquiries to county archaeologists and museum curators produced further information, often with reference to recent or even current excavations. Finally, enquiries to the commercial companies carrying out the excavations were answered with details of the discoveries, and often, very generously, with details about further sites as yet unknown to the author. More than half the sites now known have been excavated since 1990. No systematic trawl of the very extensive grey literature has been undertaken, and the list of sites in Table 1 makes no claim to being exhaustive.

These items have often been referred to as ‘plaques’, following the original terminology of 1868, but also as ‘slabs’, ‘tablets’ or ‘tiles’. The term adopted here is ‘plates’, in line with a recent suggestion (Poole in Simmonds et al. 2011, 138 and 265), more in keeping with modern practice and following the established terminology of ‘oven plates’ for somewhat similar objects from other periods. Detailed references for the finds are given in Table 1, and these will not be repeated in the text, unless required for some specific point.
Form
There are fewer than ten examples that are complete or nearly complete, compared to many hundreds of fragments, but they are enough to demonstrate the characteristic features of this artefact type (Fig. 1). Most examples are found as small fragments with sufficient of the features of shape and perforation surviving to allow their correct identification; even very small fragments with evidence of characteristic features may be identified with some confidence, as at Crescent Road, Heybridge, or Thorpe Lea Nurseries, Egham, but it is possible that other small fragments without such clear evidence have been recovered but gone unrecognised among other assemblages of pottery or fired clay. Though varying somewhat in size, the vast majority of the known examples exhibit a marked similarity in form.

The plates are roughly rectangular in shape; corners are sometimes sharply defined, but more often slightly rounded. A small number of fragments have a more oval shape; this form seems to dominate the assemblage from Queen Mary’s Hospital, Carshalton, though other examples are known from Home Farm, Laleham, Heathrow Terminal 5 and the Darenth A2/A282 Improvement Scheme. Although most examples, where the full form can be reconstructed, show straight or slightly convex sides, some of the examples from Queen Mary’s Hospital, Carshalton, show a semi-circular notch in the centre of one of the short sides, a feature known also in one example from the A2/A282 Improvement Scheme at Darenth in Kent. Its function is obscure, but may have been to fix the plate firmly in place in some larger structure.

The smallest known example is one from Yiewsley, measuring 145 by 135 mm; two others from the same site are slightly larger, at 150 by 145 mm. The largest known are from Queen Mary’s Hospital, Carshalton, where two nearly complete examples measure approximately 220 by 190 mm. Other near-complete examples from Mucking North Ring, North Shoebury and Dagenham Heathway fall within these limits, with roughly the same proportions. A complete example found at Frindsbury, Kent, in the nineteenth century was illustrated without a scale. The plates vary in thickness from about 15 to 30 mm, but the vast majority are about 20 mm thick. The edges are in general roughly rounded, although some examples show a more clearly defined profile, with a squared or sloping edge. Some pieces show a groove along one edge, discussed further below.

The plates are perforated by a number of roughly circular holes, formed by an implement such as a stick before firing, though it is also suggested that some may have been formed round a circular core; diameters are in the range 13 to 40 mm, but typically 15 to 20 mm. The perforations are usually formed from one side, creating a ridge around the hole on the other side of the plate, though this is sometimes smoothed off. The pattern of perforations can only be discerned on the more complete examples. Some are regularly geometric: examples similar to the arrangements on modern dice are known for four (Frindsbury and Queen Mary’s Hospital, Carshalton), five (Yiewsley) and six (North Shoebury) holes. One of the plates from Yiewsley showed seven holes, in two rows of three with one central; at Caesar’s Camp, Heathrow, an incomplete example showed a row of two and a row of three holes and, if symmetrical, would have had another row of two; the original object from Kingston Hill shows eight perforations, in two rows of four. The fragment from Heybridge Marina shows at least ten perforations. Other examples seem to have a more irregular pattern of perforations, as at Queen Mary’s Hospital, Carshalton, perhaps correlated with the more rounded shape of the complete plate. As the number of perforations increased, so the plates became more fragile. Mean fragment weight, where figures are available, tends to be in the range 40-50g.

There are few signs of manufacturing technique, other than the smoothing of the perforation ridges mentioned above. Some fragments show signs of finger-tip impressions and most of the plates seem to have been formed simply by hand, though one example from Queen Mary’s Hospital, Carshalton, shows signs of having been shaped by a knife. The plates appear to have been roughly shaped from a ball of clay; some are clearly thinner at the centre and thicker around the edges, as though formed by pressure from the centre. One example from Mucking North Ring shows impressions of wattle-work on one surface; this seems most likely to be the result of the surface on which the plate was formed rather than a structural fixing. Some examples are more carefully finished: fragments from North Shoebury are characterised by one surface (the ‘top’) being slurried to produce a smoother finish, while the other surface (the ‘bottom’) was profusely gritted, a feature also noted at Queen Mary’s Hospital and Westcroft Road, Carshalton; this feature recalls the heavily gritted exterior surfaces seen on the bases of some pots in the Late Bronze Age and Early Iron Age.

One recurring feature of the plates is the presence of a more or less pronounced groove along one or more edges, usually along one of the long sides; at Queen Mary’s Hospital, Carshalton, and Mucking North Ring the groove occurs in the short side. This may have been a functional trait, perhaps allowing the plates to be fixed into some larger structure or enabling them to be used in multiples, rather like modern tongue-and-groove boarding, to form a larger area, although the more rounded shape of some examples might make this unlikely. Alternatively, it may be a product of their manufacture, perhaps being formed against a framework of rods to shape one or more sides of the object; or again, it may have resulted accidentally from the plate’s being flattened on one side and then turned and flattened on the other.

Apart from these variations in general shape, presence and location of the edge groove, presence or absence of a notch and the number of perforations, there are few other variants to the standard form. One fragment from Westcroft Road, Carshalton, has been interpreted as the end of a narrow bar with a single row of perforations. Another fragmentary example from Dartford Football Club has been reconstructed as part of a small strip with two perforations, though it might possibly be the corner part of a larger plate with a notch.
Fabric and use-wear
The plates are generally made from a fabric with a sandy matrix and a tempering of crushed flint, occasionally incorporating other temper, and very often indistinguishable from a fabric used for pottery at the same site. The flint is often finely crushed, though examples with much coarser flint grains are known; quantities are mostly sparse, though again examples with much denser quantities are known. The only other fabric used was one with a similar sandy matrix and a vegetable temper. This was particularly common in Essex, at sites around Chelmsford and also at Mucking North Ring on the Thames Estuary, but also found occasionally elsewhere.

The fragmentary nature of many of the finds has undoubtedly made their detailed study more difficult, but it is noticeable how few comments there are on any visible signs of use wear by the various specialists who have studied and published these objects. In the original publication of the plates from Queen Mary’s Hospital, Carshalton, Robarts (1905, 394 and 6) described them as ‘all very much burnt’ and ‘very thoroughly burnt’, although it is not clear whether he was referring to evidence of manufacture or of use. Elsewhere, there are only very occasional mentions of signs of burning: at Mucking North Ring it was specifically noted that few of the many examples were burnt (Bond 1988, 39), while the lack of signs of burning was also remarked at Caesar’s Camp, Heathrow, and other sites (Grimes and Close-Brooks 1993, 354) and also at Home Farm, Laleham; at Hurst Park, East Molesey, it was reported that none of the fragments showed signs of having been exposed to high temperatures (Laidlaw in Andrews and Crockett 1996, 92). Visual inspection of plate fragments from a number of other sites by the author suggests that few, if any, examples show signs of wear, discolouration or encrustation that might arise from use rather than from manufacture or post-depositional processes. The evidence, if broadly consistent, is anecdotal rather than systematic, and the question would be worth further research, perhaps through the analysis of a large collection from a single site in direct comparison with the contemporary pottery assemblage.

Two sites further upstream in Berkshire, at Moulsford and Pingewood, were wrongly included in an early attempt to map the distribution (Champion 1980, Fig. 9); this was based on misunderstanding by the author, and further information, including publication (Johnston 1983-5), has now made it clear that there were no finds of this type at these sites, which should therefore be removed. There is also a possible additional example of this type of plate from Reading Business Park: this small fragment of fired clay with a perforation was originally published as a fragment of a loomweight (Bradley and Hall in Moore and Jennings 1992, 87 and Fig. 52, 1), but subsequently reinterpreted as a possible perforated plate fragment (Barclay in Brossler et al. 2004, 94), together with a further possible plate rim fragment.

Within this zone, the distribution of plates is somewhat uneven. The number of fragments found on each site varies considerably, and this will be discussed further below. At a larger scale, the plates are most common in southern Essex and northern Kent, where several of the largest assemblages occur. They are less frequent further west, and, despite many findspots, there are only two sites with large assemblages west of central London.
Chronology
Some of the older finds understandably have very limited contextual information and hence cannot be reliably dated. Thus, Frindsbury, Yiewsley and Coombe Warren, Kingston, for example, all have vague late Bronze Age associations, but no certain contexts; finds from early excavations at Queen Mary’s Hospital, Carshalton, and Mill Hill, Deal, certainly belong in the final stages of the Bronze Age, though greater precision is impossible. Contextual evidence improves with examples that have come from more recent excavations. There are no finds from contexts with classic Deverel-Rimbury associations or dates. Perhaps the earliest suggested example is that from Thorpe Lea Nurseries, Egham, found in a pit with a small assemblage of pottery and assigned to the Middle Bronze Age on the grounds of that association and its location near other, more securely dated features. This comparatively weak evidence for a Middle Bronze Age beginning is in contrast to many other sites which have firm associations with pottery which can be assigned to the Post-Deverel-Rimbury plainware phase of the late Bronze Age, between 1100 and 800 BC (Barrett 1980; Needham 2007); these include Runnymede and Petters Sports Field, Egham; Caesar’s Camp and Terminal 5, Heathrow; the Southwark sites; Olympic Park; and Tollgate, Cobham Golf Course, the Isle of Grain – Shorne Pipeline sites, Hoo St Werburgh, the Dartford Football Club site and the A2/A282 Improvement Scheme, Darenth, all in Kent, and Springfield Lyons in Essex. At South Hornchurch, the plates are found in contexts dating to Phases 2 and 3 of the site sequence, which extends from the plainware phase into the succeeding decorated ceramic phase, equivalent to the earliest Iron Age. At Monkton and Highstead the ceramic associations would again suggest the possibility of a date in the decorated phase.

There are no clear associations with pottery of the early Iron Age. The example from Ivy Chimneys, Witham, Essex, came from a disturbed context; although no late Bronze Age phase was recognised at the site, where the main occupation began in the middle Iron Age, it is possible that there had been an earlier phase of activity with artefacts redeposited in later contexts. The finds from La Panne in Belgium came from early excavations and are without secure context; reappraisal of the site suggests that, although activity may have started in the earliest phase of the Iron Age, the bulk of the ceramic and metalwork evidence is consistent with a date from Early La Tène onwards (Kerger 1999).

The plates can therefore be most securely dated to the final phase of the Bronze Age and the very beginning of the Iron Age. How early they started is not yet clear. It is possible that they continued throughout the plainware ceramic phase and somewhat later, thus spanning a period of perhaps 1100 to 700 BC; the main period of their use may also have been much shorter, towards the end of this phase.
Late Bronze Age context
The distribution of the plates merits further discussion to place them in their Late Bronze Age context. It is strongly correlated with the density of evidence for field systems of the later Bronze Age and the patterns of deposition of metalwork. The correlation between the distribution of fields and metal has already been discussed by Yates (2007, 112-20). In Kent, the distribution of the plates closely matches the pattern of fields and bronzes in the north of the county: this is concentrated around the Isle of Thanet and the Wantsum in the north-east and in the Isle of Sheppey, around the Medway and the Hoo peninsula in the north-west. In Essex there are notable concentrations of evidence for fields and bronze deposits around the Blackwater and in the area around Southend, both matched by finds of plates (Yates 2007, 73-7).

The valleys of two tributaries of the Thames are also conspicuous for their concentrations of metalwork and land division, the River Lea (Yates 2007, 114 and Fig. 12.4) to the north and the River Wandle, especially its upper reaches, to the south (Yates 2007, 114 and Fig. 12.5). The Lea valley has so far only produced a single findspot of plate fragments at the Olympic Park site, but to the south there is a cluster of sites in the upper Wandle valley around Queen Mary’s Hospital, an area notable for its unusual deposits in addition to the metalwork (Proctor 2002).

There is much less evidence for fields in central London, possibly because of the more restricted nature and scale of excavations, but the findspots of plates in Southwark correspond to a notable cluster of sites with evidence for Bronze Age activity including cultivation (Yates 2007, 32); they are also close to a concentration of bronze objects from the Thames and more especially from sites on the north bank: ‘what is eye-catching is the great cluster of land finds that has appeared in the area of the City’ (Needham and Burgess 1980, 455).

There are a number of further sites, albeit mostly with a comparatively low density of plate fragments, on the western outskirts of London, from Kingston to Egham, many of them within the large area of fields found on the west London gravel terraces (Yates 2007, 32-6), such as those at Heathrow Terminal 5 and neighbouring sites.

These geographical patterns of Late Bronze Age activity have mostly been revealed by modern development-funded archaeology, and are therefore influenced by modern social and economic factors as well as past reality. To what extent the blank areas were really unoccupied, or only minimally exploited, at that time is still uncertain. Yates’s methodology was designed to include fieldwork reports where no Bronze Age features were identified, thus suggesting genuinely blank areas, but there are other parts of the lower Thames valley where comparatively little fieldwork has taken place because of the nature of modern landuse and development, for example in the suburban and parkland areas of much of south-western London.

Within this lower Thames region, however, the distribution is not even, and there is considerable variation in the number of plates or fragments found at each site. Quantitative comparison by site is clearly problematic as numbers will be determined by many factors such as post-depositional history, scale of excavation, recovery strategy and recognition in post-excavation processing, as well as original usage and deposition. Nevertheless, there are striking variations in quantities of plates recovered. Most sites have produced less than ten fragments; only thirteen sites have produced more than fifteen fragments. In seven cases these are known Late Bronze Age defended enclosures or ringworks, the type of site that Yates (2007, 18) has called ‘aggrandised enclosures’: Springfield Lyons, Lofts Farm, Mucking North Ring and South Rings, South Hornchurch, Highstead and Queen Mary’s Hospital, Carshalton. The exceptions are North Shoebury, where 133 fragments were recorded in rescue excavations, and where the nature of the Late Bronze Age occupation was uncertain; Chadwell St Mary; the Beddington Sewage Works site near Queen Mary’s Hospital Carshalton; and Hurst Park, East Molesey, Surrey. There are also two sites, Home Farm, Laleham, and Isle of Grain – Shorne Pipeline Site H, where quantities have been affected by the discovery of large concentrations in specific contexts. It is possible that the aggrandised enclosures have attracted a larger scale of excavation than some of the smaller sites, thus affecting the quantity of finds, or that large deposits have been missed in small-scale excavations, but it is noticeable that even extensive areas of Late Bronze Age landscape have produced few examples, such as the 47 ha examined at Heathrow Terminal 5, which produced only three fragments. It is quite possible, therefore, that the apparent concentration of finds on such exceptional sites is a real association and a reflection of the density or frequency of the activity that produced and used them. This suggested correlation with defended enclosures will be discussed further below.

The plates are clearly different from other types of perforated object sometimes found in later prehistoric assemblages. They are flat plates rather than vessels, and therefore unlike the pottery bowls with perforated bases known from Iron Age contexts, where the perforations are in any case generally somewhat smaller. Perforated plates were also used for tablet weaving. They are not common finds in Britain (Cunliffe 2005, 487 and Fig. 18.1, 24), but are known more widely in western Europe (e.g. Grömer 2010, 107-12), most frequently in bone but occasionally in fired clay (e.g. Castillo Rollán 1996). They differ from the plates under consideration here, however, in a number of ways: in size and weight, being generally much smaller, thinner and lighter; in shape, being regularly symmetrical, typically triangular or square, rarely rectangular; and in the location of the perforations which are few in number and placed near the edges or vertices of the tablet and perhaps centrally.